Punctureproof pneumatic inner tube



May 20, 1930. w. J. ASCHEN B'ACH' PUNCTUREPROOF PNEUMATIC '.INNER TUBEFiled April 30. 1925' Patented May 2t), 1930 i i3 ED ATES. PATENT vere-ice wnmnn a. esonrnnaon, or nasr ORANGE, new JERSEY frunorunn'rnoozPNEUMATIC INNER TUBE Application filed ai 30,

' This invention relates to puncture-proof pneumatic inner tubes" forautomobile tires and the like. i l i My invention is particularlyadapted to tire 5 311085 [in general use at the present time andis'similarly'adapted to other forms of tires for automobiles,motor-cycles, bicycles and the like. '1

My invention is improvement over the I form of inner tubes set forthinthe U. S.

PatentNo. 956,884, John H. Brow-n,.dated May 3rd, 1910,theU. S. PatentNo. 1,121,467, John H, Brown, dated December th, 1914-, theU. S.PatentNo. 1,155,775, J. lvoorhees,

is dated October 5th, 1915,, and s. Patent No. 1,238,099, John H. Brown,dated August 28th, 1917. i Pursuant topneumatic tires as setforth v inthe aforesaid patents, the length of the. I zchollow composite bodyformed of laminae of rubber and of, canvas applied to the treadportionof the tube is cutof lengths for the upon turning the tubinginside out, in lthe manner of turning a 'stocking'font, th'ethere;tofore outer rubber portion is located inwardly of the tubing andby'reason of the non-elasticity of thecanva's the inward per tion of therubber is held undercompr'ession and rendered self-healin'g in the eventthat any nail or other article should pierce through the shoe or othertireand also pierce the inner r tube through. its tread portion. Forsuch purposes, a special fabric, namely sea island canvas of unusuallyhigh tensile strengthwas deemed necessary for-the purpose of attainingthe characteristic of proof against punce ture.

1928. Serial No. 105,626. I

However, in the manufacture of such tubes having such'non-elast cfabric, unsatisfactory results were'obtainedin the event that theprecise length ofthe formed tubing'orlth g extent of 'splining at theoverlapping joint, or both, were departed from, thus giving rise toatube which was either too long or'ltoo short'than theinnercircumference ofthe shoe in which it was placed and r esulting'iin thebreaking down of the'fabric either immediately after installation orafter a hore period of use. Further difliculties were en countered byreason of thevariation of the inner circumferential dimensionof'tire'shoes,

inevitable pursuant to the method of manu-' facture of thesame, and alsoarising upon-the inevitable elongation ofthe shoe'aft'er partial wearingand consequent breaking down of mensions of tire shoes also arise, owingto the absence of standardization among manufacturers for purportedlythe same sizes. 7'

Pursuant to my invention, the fabricinter posed between laminae ofrubber orother el'astic material is cut on. the bias relat'iveto itswarpand weft, whereby'uponlanchoringthe lateral edges of the fabric withthe immediatelyg-adjacent laminaeof rubber, the .fselfhealing?characteristic of the inner portion of the rubber laminae ontheinteriorofthe tube is maintained notwithstanding varia 'tions in the length"ofthetubingor the extent of the overlap of the joint in themanufacthesame in use. Variations of theinner di 1 V tureof the, tube,and also notwithstanding any expansions of the shoe in the use of myimproved inner tube. Theseadvantages of my invention also obtainnotwithstanding the variations of dimension, particularly fortheinnerrfaces, of the various makes of tire shoes.

Pursuant to my invention, supplementallayers of fabric, also preferablycut 'on the bias, are interposed between theafores aid or main strip offabric and the adjacent laminae of rubber, thereby increasing theanchoring joint betweenthe lateral edges of the main'fabric strip andthe immediately disposed laminae of rubber; Theme of su plemental oriillet strips out on the bias not only increases the strength of thereinforce the aforesaid Brown and Voorhees patents.

' In forming such layers of rubber,'I prefer to i r at least equal tothe elasticity of the main means which has a; egree of elasticity inboth transverse and longitudinal directlons strip of fabric.Consequently, the stretch throughout the tube is uniform along'themargins of the main'piece of fabric. The inr I m by scalloping itsedges; v a I I prefer to vulcanize the sphned ends of the tivelaminae ofrubber and fabriccorrespondvention is, "therefore, distinguishable fromthe prior practice, which involves the weakening ofthe main strip alongits margins, as

longitudinal or lateral in Figs, 1 and 2. Such strips 12, 13 aresubstantially uniformly disposed relative to the central portion of thetubing 11, which subsequ'ently becomes the vcircular apex of theoverlapping joint of the tubing in forming theinner tube, in lieuoflsecuring the same together by cement or the like.

a inventioniscarried out with optimum results by forming the success velayers or laminaeof'rubber and fabriconacircular, an-

of engagementan'dsecurement oftherespecnular 'mandril, to therebyconform the areas ing to the positions ofthe same whenin use 2 within a"tire shoe orthe like.

- Further features and 0b 7 ects of the invention will be more fullyunderstood from the following detail description and the accomin which 71 is'a diagrammatic view'illu'strating an annulanmandril ;on whicharelaid suc-. cessive laminaeo'f rubber and fabric of such number asmaybe desired, pursuant to my invention, the successive laminae beingindie cated'in Fig. ,1 na: direction from the right toward the left."Theparts indicated at'the.

eXtreme'left-hand side of Fig. :1 show the rfinall'yeformed laminae ofrubber and fabric j preparatolry' for the vulcanizingstage';

: Fig. 2 is a sectionalvelevationon line ofFigl; p Fig. 3 is a sectionalelevation on' line 3+3 of Fig 1, showing the laminae of rubber and V inposition fabric in correspondence to the assembly of the same prior, tovulcanizing, thex'm'a-ndril being omitted, and also showing such laminaetube after vulcanizationgand w under substantially no' load. j 7

Referring to Figss'l' and'2, the order of assembly of 'the respectivelayers or laminae of Fig' 4 is ,a'transverse sectional elevation of aninner tube embodying my invention, this view illustrates my compositeinner tube under full inflation'within attire casing and rubber ispursuanttothatgenerally stated in use such rubbercomposition which whenvul r canized yields livevrubber. However, pursuant-to my invention,thc'mandril 10 is an- 1 nular and circular in' cross-sectioni The an--nulus 1s sllghtly longer circumferentially rovides a reinforcing thatof the in correspondence to the inner threads.

diameter of the desired or resulting inner tube. The first layer ofrubber composition is indicated at 11; this layer extends for the 7complete length of the tubing, and exceeds length of the desiredinnertube by the extentof overlapping of the joint, as

will appear more fully-hereinafter.

Preferably, I provide a lower eral periphery of the tubing 11, asindicated tubing, and are disposed to extend inoverlapping relationrespectively relative to the op I layer of i spacedstrips of fabric-12,13, each strip 12, 4

l'3'extending' circumferentiallyabout a latpositely disposed lateraledges 14,115 of theff a main strip of fabric 16 p Such strips 12,13 arehereinafter termed for brevity as supplemental fabric strips.

Upon such supplemental fabric stri'ps'12, 13, Ilay the layer orlamina 17of rubber i I V composition and uponthe central portion of V such rubberlayer 17,I -lay the main strip of fabric 16 to disposeitslateral edges14, 15..

respectively 'within the widths of fthe lower fabrlcf strips 12, 13. gThe lengthiio'f the fabric 16is cut on' the bias, that is to say v andweft threads ofithe woven structure "of itsedges 1'4, 15' are out atan'angleto theiwarp the main fabric strip 16. 7 As appearsin thedrawings, the lateral edges 14, 15 of the main fabric strip 16 arepreferablycut' straight "I {also prefer to cut straight the lateraledges of the re-inforcingstrips'12,13,19, 20. Above such main strip16*of fabric, Ijdispose theoutward layer or lamina 1 8 .of rub berf' andupon such outwardlayer 18, I dis 2.

posethef oppositelyfdisp-osed strips 19, 20 of fabr c respectivelyoutwardly of the previous- 5 ly disposed, inward fabric strips 12, 13andpf similarly to overlap theopposite edges 14,15 of the maln fabricstrip 16. Such strips 19, 20, of fabric are" also preferably cut "on"the bias relativeftoytheir warp and weft Upon such outward-strips 1 9,20, lay

another layer 21 of rubb'er'compositions g 'I V prefer-t0 employ "canvasfor :such main ii 7 ip and he respective sets of fabric 3? v 7 strips12, 13 and .19,'-20 a V 1 a In building-u the aforesaid layers 61laminaeof rubber compositionand fabric, the

then transferred from the'fiat support to'a'n same are applied toflatbed or other suit-f able support.- It is understood that such'rubber composition comprises a suitable vul-Y r canizing substanceor'mediumsuch as antimony or'thelike'. Thelbuilt up or -su'perf imposedlaminae-or layers of rubber composia tionand fabric applied to thetubing11are V V annular man'dril, the circumferential length of whichexceedsthatof the'desired br re-V sulting inner tube by the extent ofthe overlapping splined joint. v h

I The annular mandril is preferably formed ofarcuate circular sections,connected by' a hinged or other suitable joint-serially with one anotherand disconnectible at one joint, to enable the resultingtubing aftervulcanization to be readilystripped from the mandril,

The widths of the layers of rubber con1- position are such as to providefor a slight overlap-at the inner circular periphery of the tubingapplied to the annular, circular mandril, thus ensuring a sealby anautoge'nous preparatory to thevulcanizing stage."

v cloth 31 is unwrapped and the tubing is and the adjacent rubbersections as shown in Fig.4 with their positions as shown in inwardlydisposed portion. the range of the extensibility limited by the strippedfrom the mandril 10. V In stripping the tubing from the mandril, therelease of the tubing from the mandril is facilitated by adirected'blast of compresed air, acting in the manner of a wedge. Thecompressed air is directed from point to point to displace thetubingfrom engagement with the surface of the mandril and force manually orotherwise is applied to the progressively increased dis-engaged portionof the tubinguntil thetubing is freed from the mandril. This op erationis expedited by the sectional assembly of the mandril.

The general arrangement of the parts of the stripped tubing is indicatedin Fig. 3.

It will be observed that the outward portion 22 of the vulcanized tubingis normally of an increased diameter and of a relatively large curvatureas compared with its inward portion 32 i. e., originally complete tubing11. In this status of the tubing, the main strlp of fabric 16 isdisposed more closely toward the inner peripheral portion 32 of thetubing than the outer peripheral portion 22.

The length of tubing is then turned inwar'dly upon itself, as in turningout a stoching, whereby the main length of fabric 16 is disposed moreoutwardly as appears by a comparison of the positions of the fabric 16Fig. 3. The theretofore inwardly disposed portion 32' of the tubing 11,has now become the outwardly disposed portion, and conversely thetheretofore outwardly disposed portion 22 of the tubing has now becomethe By reason of main strip 16 of fabric, the inwardly dis posed portion22'is held under compression,

which compression is enhanced by the com-u pression of the air withinthe interior of the resulting tube when in use, as will be apparent.

In the vulcanizing stage, the lateral edges 14,15 ofthe' main canvasorother fabric strip 16 are permanently secured to the im mediatelyadj'acentlayers of laminae of rubber, and likewise throughout theopposite faces of the fabric strip 16.- To insure'a perma'nentoint atthe lateral straight edges 14,-

' 15, theoppositely disposed sets of supplemental fabric strips 12, 13and 19, 20 bridge 7 the portions of the rubber laminae which-arerespectively anchored to the lateral edges 14, 15, thereby're-enforcingsuch anchored por tion of the laminae of rubber and therewith the jointof the same with the lateral straight edges 14, 15 of the fabric strip16; such function ofthe sets of supplemental fabric strips 12, 13, and19, 20 is augmented by cutting the supplemental fabric strips on thebias and 7 cutting straight the lateral edges of the sup plementalfabric strips 12, 13, 19, 20.

From the above, it willappear that with theuseof canvas or other fabricserving as.

means for theinwardly the'main retaining disposed rubber of my innertube, being cut on the bias, the fabric conforms itself to assumeoptimum positions relative to the imme 'diately adjacent laminae ofrubber in the stage of building up the laminae of rubber and fabricWhile supported on a flat bed and also in the stage of transferring thebuiltup laminae from a positionof flat support to V V a position on theclrcular annulus mandril. Such self-accommodation of the fabricalsoaffords a wider range of self-adjustability of inner tubes withoutbreakage or other damage to the fabric by reason ofvariations of thelength of the tubing from which the inner tube is cut, variations in theextent of the overlap at the Splined or other joint and in the variationof sizes of the various makes of shoes and variations ensuing upon thecontinued expansion of the tire shoe inuse.

'It will also be observed that inner tubes embodying myinvention have acomposite due to strains arising.

structure comprising one portion which.

servesas a complete inner tube, andfurther comprising another portionwhich serves.

as the compression element or portion; the bias cut tiguous faces of myinner tube and to maintainthe com pression element or portion at thedesired degree of compression," whereby the inner tube portion undervarying road conditions is maintained at substantially uniform tension,for any given load. 7 V

The parts of my invention illustrated in Fig. 1 conform generally to aninner tube for fabric serves to join the conof these composlte portionswidth, the sets of'supplement-alfabric strips j 12,13 and 19, 20 being'posedfrelative to the lateral edges 14:, 15 of acord type of tire shoefFor balloon sizes of tireshoes, andgenerally for use where the airpressure is desired tobe decreased,the tread portion "32, :see Fig. :4,may be 'increased in arcuate length, and the mainfab ric strip 16correspondingly increased in its correspondingly disthe fabric strip,16. *Forsuch increased.

widths of the-fabric 1 6, the bias strip'16 sinnlarly attains highestresults, by reason of its self-adjustment during the stages of manustrains uponthe warp and facture to conform to the desired varied po--sitions, thus imposing substantiallyequal weft; threads of and also ofthesup-- the main fabric strip 16 12, 13, 19,20, and

plemental fabric strips without engenderingy'undue strain on any of myinvention, the fabric strip 16 may be of portionof the Warp and weftthreads and also lnjuse, as ensues upon the turnmg of the the warp andWeft threads individually ter- 7 I minate at substantially uniformdistances 3 and afforda relativelyhighdegree of-edge strength understretching strains, andsup plemental strips of fabric disposedwithinsaid tread and overlappingthe lateral edges 1 of said first mentionedlength offabric,sa id supplemental strips also having their warp andweft threads extendingon the bias and providlng additional strengthalong the edges ofthe mam strip with a'degreje ofelas from thelongitudinal center of the fabric ticity not less than the elasticity ofthe main n strip whereby thestretch in the plane'of the margins ofthelatter is substantially uniform throughout the tube. In testimonywhereof Ihave signed this speclfication this 28th day of April, 1926'.

' ,VVALTER J. ASCHENBACH. .I

wheel to bring successive portions of the shoe V to relatively flattenedposition when in con tact with the roadway and consequent relativeflattening of the inner'tube. Bylmeans a'length to extend arcuatelysubstantially one-half of the circumference of the trans- I verseperiphery of the tube, thus providing for the puncture proof protectionto substan- 'tially the full height of the side Walls of the derived by,distr' the fabric strip 16 is subjected over the weft 7 threads as Wellas the son of the fabric strip 16 inner tube as well as overthe treadportion warp threads, by reabeingcut on the bias, as compared witha no-bias cut fabric strip as heretofore proposed wherein the strain isborne substantially solely by the Warp- 7 threads.

said length of fabric being'und'er ric having itswarp v. I claim: i a

A puncture p oof pneumatic inner tube of resilient material having arelatively thickened =outer V peripheral i tread and relatively thinsidewalls, a substantially continuous lengthoffabric disposed withinsaid rela tively thickened outer peripheral tread, the portion of saidtread disposed inwardly of a relatively highcompression, said length offaband weft threads extending on the bias to the direction of its lengthwhereby both said warp and weft threads extend at an angle to thecircumferv ential direction of the'outer periphery of the thread andprovide both transverse andjlongitudinal resiliency, the lateral edgesof said fabric 'being substantially straight whereby flan

